Seats having an integrated seat belt, which are used in particular for convertibles or commercial vehicles, are known in many designs from the state of the art. In the case of such seat belts, the belt progresses partially inside the seat, wherein an automatic retractor of the seat belt is generally fastened on the bottom part of a seat frame. The seat belt then progresses upwards within a backrest and exits from it towards the front in the upper part of the backrest.
To increase comfort, some known seats having an integrated seat belt have devices for changing the curvature of the backrest surface, wherein for this the backrests can be designed in multiple pieces, which enables an adjustment of the angle of the different backrest sections relative to each other.
To ensure the free mobility of the belt in all possible orientations of the backrest, a device for guiding the seat belt inside the adjustable backrest is needed. Otherwise, there is a risk that the seat belt will become pinched inside the backrest between a seat-internal support structure of the backrest and an outer padding of the front side of the backrest or an outside cover of the back side of the backrest. To secure the function, it is already known to use an inherently stable, flexible plastic channel to guide the belt inside the backrest. However, this is very expensive and installation is complex.